EDAC, altera: Fix an error handling path in altr_s10_sdram_probe()

EDAC, altera: Fix an error handling path in altr_s10_sdram_probe()

If regmap_write() fails, we should release some resources as done in all
the other error handling paths of the function.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Thor Thayer <thor.thayer@linux.intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/20180610174532.22071-1-christophe.jaillet@wanadoo.fr
Fixes: e9918d7fafae ("EDAC, altera: Handle SDRAM Uncorrectable Errors on Stratix10")
Signed-off-by: Borislav Petkov <bp@suse.de>